1. Field of Invention
The present invention relates to a wireless telecommunication area, and more specifically to a method of dealing with the carrier conflict between the main and subordinate cards of a dual-card-dual-standby mobile phone.
2. Description of Related Arts
Any discussion of the prior art throughout the specification should in no way be considered as an admission that such prior art is widely known or forms part of common general knowledge in the field.
Wireless telecommunication industry developed very fast driven by the technology, market and mobile services. The mobile telecommunication devices have become a necessary part of daily life. With the increasing demand for mobile telecommunication service, many persons need two mobile phones at the same time. For example, in order to save the expensive roaming fee, the persons who usually work at different cities may need different local SIM cards at different cities respectively, so that they can user local SIM card at every city. However, changing SIM card frequently or bringing two mobile phones are very troublesome. Therefore, a dual-card-dual-standby mobile phone has been developed.
A US patent application US20060234693 discloses a single mobile phone supporting different subscriber numbers, having two SIM ports, sharing DSP and application processor and connecting to two RF modules respectively through one switching circuit. However, such mobile phone can only support two subscriber numbers respectively, and can not satisfy the demand of dual-card-dual-standby.
The current dual-card-dual-standby mobile phone usually uses two chipsets. For example, a Chinese patent application CN20061015647.0 discloses a technique scheme of two SIM cards serving at standby mode at the same time, wherein a dual-card-dual standby mobile phone includes a main device comprising a main SIM card port, a corresponding main antenna, a RF module and a baseband processing module, and an subordinate device having an subordinate SIM card port, an subordinate RF module and a subordinate baseband processing module, wherein the main baseband processing module communicates with the subordinate baseband processing module via a communication module. As shown in FIG. 1, the main device and the subordinate device use their own baseband processing module respectively, which results in high cost and large size of the dual-card-dual-standby mobile phone.
Therefore, a dual-card-dual-standby mobile phone with a single chipset is developed. A dual-card-dual-standby mobile phone with a single chipset adopts one set of antenna, RF module and baseband processing chip and other peripheral devices. In order to make sure that two SIM cards camp in their own cell respectively at the same time, the single RF chip has to be able to receive the system informations and paging messages from two carriers periodically. However, no matter whether the two carriers belong to the same operator or different operators, a single RF chip receiving two carriers has not been considered in designing the GSM network, especially in case of the two carriers belonging to different operators. Therefore, the system informations and the paging messages of two carriers may conflict with each other.